1 files changed, 167 insertions, 0 deletions
diff --git a/src/lib/hooks/callout_handle.cc b/src/lib/hooks/callout_handle.cc
new file mode 100644
index 0000000..6877b65
--- /dev/null
+++ b/src/lib/hooks/callout_handle.cc
@@ -0,0 +1,167 @@
+// Copyright (C) 2013-2022 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <hooks/callout_handle.h>
+#include <hooks/callout_manager.h>
+#include <hooks/library_handle.h>
+#include <hooks/server_hooks.h>
+
+#include <string>
+#include <utility>
+#include <vector>
+
+using namespace std;
+
+namespace isc {
+namespace hooks {
+
+// Constructor.
+CalloutHandle::CalloutHandle(const boost::shared_ptr<CalloutManager>& manager,
+                    const boost::shared_ptr<LibraryManagerCollection>& lmcoll)
+    : lm_collection_(lmcoll), arguments_(), context_collection_(),
+      manager_(manager), server_hooks_(ServerHooks::getServerHooks()),
+      current_library_(-1), current_hook_(-1), next_step_(NEXT_STEP_CONTINUE) {
+
+    // Call the "context_create" hook.  We should be OK doing this - although
+    // the constructor has not finished running, all the member variables
+    // have been created.
+    manager_->callCallouts(ServerHooks::CONTEXT_CREATE, *this);
+}
+
+// Destructor
+CalloutHandle::~CalloutHandle() {
+    // Call the "context_destroy" hook.  We should be OK doing this - although
+    // the destructor is being called, all the member variables are still in
+    // existence.
+    manager_->callCallouts(ServerHooks::CONTEXT_DESTROY, *this);
+
+    // Explicitly clear the argument and context objects.  This should free up
+    // all memory that could have been allocated by libraries that were loaded.
+    arguments_.clear();
+    context_collection_.clear();
+
+    // Normal destruction of the remaining variables will include the
+    // destruction of lm_collection_, an action that decrements the reference
+    // count on the library manager collection (which holds the libraries that
+    // could have allocated memory in the argument and context members.)  When
+    // that goes to zero, the libraries will be unloaded: at that point nothing
+    // in the hooks framework will be pointing to memory in the libraries'
+    // address space.
+    //
+    // It is possible that some other data structure in the server (the program
+    // using the hooks library) still references the address space and attempts
+    // to access it causing a segmentation fault. That issue is outside the
+    // scope of this framework and is not addressed by it.
+}
+
+// Return the name of all argument items.
+
+vector<string>
+CalloutHandle::getArgumentNames() const {
+    vector<string> names;
+    for (ElementCollection::const_iterator i = arguments_.begin();
+         i != arguments_.end(); ++i) {
+        names.push_back(i->first);
+    }
+
+    return (names);
+}
+
+ParkingLotHandlePtr
+CalloutHandle::getParkingLotHandlePtr() const {
+    return (boost::make_shared<ParkingLotHandle>(server_hooks_.getParkingLotPtr(current_hook_)));
+}
+
+// Return the context for the currently pointed-to library.  This version is
+// used by the "setContext()" method and creates a context for the current
+// library if it does not exist.
+
+CalloutHandle::ElementCollection&
+CalloutHandle::getContextForLibrary() {
+    // Access a reference to the element collection for the given index,
+    // creating a new element collection if necessary, and return it.
+    return (context_collection_[current_library_]);
+}
+
+// The "const" version of the above, used by the "getContext()" method.  If
+// the context for the current library doesn't exist, throw an exception.
+
+const CalloutHandle::ElementCollection&
+CalloutHandle::getContextForLibrary() const {
+    auto libcontext = context_collection_.find(current_library_);
+    if (libcontext == context_collection_.end()) {
+        isc_throw(NoSuchCalloutContext, "unable to find callout context "
+                  "associated with the current library index (" << current_library_ <<
+                  ")");
+    }
+
+    // Return a reference to the context's element collection.
+    return (libcontext->second);
+}
+
+// Return the name of all items in the context associated with the current]
+// library.
+
+vector<string>
+CalloutHandle::getContextNames() const {
+    vector<string> names;
+    const ElementCollection& elements = getContextForLibrary();
+    for (ElementCollection::const_iterator i = elements.begin();
+         i != elements.end(); ++i) {
+        names.push_back(i->first);
+    }
+
+    return (names);
+}
+
+// Return name of current hook (the hook to which the current callout is
+// attached) or the empty string if not called within the context of a
+// callout.
+
+string
+CalloutHandle::getHookName() const {
+    string hook = "";
+    try {
+        hook = server_hooks_.getName(current_hook_);
+    } catch (const NoSuchHook&) {
+        // Hook index is invalid, so this methods probably called from outside
+        // a callout being executed via a call to CalloutManager::callCallouts.
+        // In this case, the empty string is returned.
+    }
+
+    return (hook);
+}
+
+ScopedCalloutHandleState::
+ScopedCalloutHandleState(const CalloutHandlePtr& callout_handle)
+    : callout_handle_(callout_handle) {
+    if (!callout_handle_) {
+        isc_throw(BadValue, "callout_handle argument must not be null");
+    }
+
+    resetState();
+}
+
+ScopedCalloutHandleState::~ScopedCalloutHandleState() {
+    resetState();
+
+    if (on_completion_) {
+        on_completion_();
+    }
+}
+
+void
+ScopedCalloutHandleState::resetState() {
+    // No need to check if the handle is null because the constructor
+    // already checked that.
+    callout_handle_->deleteAllArguments();
+    callout_handle_->setStatus(CalloutHandle::NEXT_STEP_CONTINUE);
+}
+
+} // namespace hooks
+} // namespace isc